import re
from collections import deque
from sys import stdin, stdout
input = lambda: stdin.readline().rstrip()
write = stdout.write

def main():
    regex = re.compile(r'1+')
    ponds = 0
    for i in range(H):
        r = 0
        while 1:
            obj = regex.search(A[i], pos=r)
            if obj is None:
                break
            l, r = obj.start(), obj.end()
            if Flag[i][l] is None:
                bfs(i, l)
                ponds += 1
    write(str(ponds) + '\n')

def bfs(h, w):
    g = deque([(h, w)])
    Flag[h][w] = True
    apnd, popl = g.append, g.popleft
    while g:
        x, y = popl()
        for i, j in {(1, 0), (-1, 0), (0, 1), (0, -1)}:
            xi, yj = x + i, y + j
            if 0 <= xi < H and 0 <= yj < W:
                if A[xi][yj] == '1' and Flag[xi][yj] is None:
                    apnd((xi, yj))
                    Flag[xi][yj] = True
    return

H, W = map(int, input().split())
A = stdin.read().replace(' ', '').splitlines()
Flag = [[None] * W for _ in [0] * H]
main()